Hand-held, battery-powered lighting devices, called flashlights in the US or torches in the UK and known as penlights in their smaller versions, are turned on and off by means of switches. These switches vary according to their design and, dependent thereon, the ease with which they can be used, that is, how readily the switch can be found, for example by feel in the dark and how easily it can be actuated, especially when the user's hands are numb from cold or handicapped by thick gloves, and whether the light can be turned on and off with only one hand.
In the case of the predominant cylindrical flashlights, with which the following is concerned, switching is most commonly actuated by means of sliding and/or pressure-sensitive devices on a side of the flashlight. Another way to open and close the circuit is by rotating either one of the end members. Such rotational manipulations may require two hands, especially in the case of larger devices. A further alternative is a pushbutton switch on the end of the flashlight opposite the light. This last variant is found mainly on small flashlights or penlights, where it affords an improvement in ease of use over the other alternatives. However, the position of the hand and of the flashlight itself is often awkward. Use of such pushbutton switches on the ends of larger flashlights aggravates the disadvantages of this switching arrangement.